# Attractive Force of Spherical Capacitors

**Electricity and Magnetism**Level 3

If a capacitor is composed of two isolated conductors, after charging the oppositely charged plates will experience a Coulombic attraction. Given a spherical capacitor of inner radius \(a\) and outer radius \(b\), find the attractive force exerted on the outer conductor assuming that each conductor holds charge \(\pm Q\).

Assume the conductors are mechanically held fixed, so the force is constant in time, and let negative forces correspond to attraction and vice versa.